Is this normal?

guitarnut57

Before I ask this question, please forgive me of my ignorance of 4 strokes, as I raced 2 strokes my entire life until I made the switch to a 2004 YZ 450 back in November and am pretty much clueless.

Here is what is concerning me. I fired-up my bike tonight before I changed the oil and filter like I do after every ride, and I don't know why I did it, but I stuck my head down next to the outside of the cylinder to listen. Every time I revved the bike a little I noticed somewhat of a clattering/knocking sound that got progressively louder the higher I got into the rpm's. Is this normal for 4 strokes? Do I need to post a vid of it? Any advice would be greatly appreciated.

grayracer513

Unless you are familiar with it, you should compare yours to another one before you worry too much about it. Also, if you have a skid plate, that can exaggerate the noise level, and if you R&R'd it for the oil change, it can sound entirely different than it did before you took the plate off.